I think this is a link order problem. Try moving -lcspice to the end of the link command:
$(CXX) $(LDFLAGS) $(LIBS) -shared -fPIC -L$(prefix)/lib -o $@ $^ -lcspice
I think this is a link order problem. Try moving -lcspice to the end of the link command:
$(CXX) $(LDFLAGS) $(LIBS) -shared -fPIC -L$(prefix)/lib -o $@ $^ -lcspice